Danfoss ECL Comfort 310 Operating Manual page 8

Operating Guide ECL Comfort 310, application A377
DHW (circuit 3):
The DHW heating circuit is connected directly to the heating
source. The temperature sensor S10 measures the return
temperature. If the return temperature limit is exceeded, the
desired temperature at S9 can be corrected.
By means of a week schedule (up to 3 'Comfort' periods / day), the
DHW circuit can be in 'Comfort' or 'Saving' mode (two different
temperature values for desired DHW temperature).
Charging start, DHW tank with 1 or 2 temperature sensors
When the measured DHW temperature S6 gets lower than the
charging-start temperature, the DHW heating pump P1 is switched
ON.
The motorized control valve (M1) is controlled in order to maintain
the heating / charging temperature at S9.
The DHW charging pump is switched ON when the S9 temperature
is acceptable, which means it must be within 3 K from desired
heating / charging temperature. See also application A377.1, ex. d.
If S9 is placed on the heat-exchanger's secondary side, it must be
placed in the heat-exchanger.
The DHW charging temperature is determined by the desired DHW
temperature at S6 plus the set charging difference. The charging
temperature is typically 5–10 degrees higher than the desired
DHW temperature.
A377.1, A377.3:
S10 can have one of two functions:
1. Act as return temperature limiter
2. Monitor the DHW heating temperature in order to avoid
discharging and enable return temperature limitation.
Function 1: The return temperature, when the DHW heating /
charging is active, can be limited to a set value.
Function 2: The DHW charging pump is switched ON when the S10
temperature is higher than the DHW temperature. After 4 minutes,
the return temperature limitation (set value) is activated.
A377.2:
The DHW heating / charging circuit is connected after heating
circuit 1. The DHW heating circuit cannot be connected directly to
the heating source. The temperature demand at S9 is transferred as
desired temperature at S3.
The DHW heating circuit has a preheating circuit, where the DHW
heating temperature at S9 is adapted to the desired DHW charging
temperature at S10. If the DHW charging temperature at S10
cannot be reached, the ECL controller gradually increases the
desired DHW heating temperature at S9 in order to obtain the DHW
charging temperature. The ECL controller remembers the adapted
S9 temperature. A maximum temperature value can be set.
A delayed start of charging pump can be arranged. Also, it can
be arranged, that the start of the charging pump depends on the
charging temperature. In this case, S10 must be placed in the
heat-exchanger.
8 | © Danfoss | 2017.10
A377.1, example d
Charging-start temperature:
Desired DHW temperature + Start difference.
Example:
50 °C + (-3 K) = 47 °C
The S10 temperature sensor can alternatively be used as a monitoring
temperature sensor to enable DHW charging. If used as a monitoring
temperature sensor, the S10 temperature sensor must be placed in
the supply pipe.
VI.GU.F6.02